Tart Cherry

Tart cherry, also known as sour, dwarf, or Montmorency cherry, is the fruit from the Prunus cerasus tree native to Europe and southwest Asia. They were a popular crop to the Greeks dating back to 300 B.C. Unlike their sweet counterpart, tart cherries are best consumed dried, juiced, or cooked, and contain superior health benefits.

Tart cherries contain vitamins A, C, E, and phenolics such as anthocyanins. The majority of antioxidant and anti-inflammatory properties are concentrated in the skin of the fruit, which is where anthocyanins are active and also deliver the dark, rich pigment seen in all berries.

Oxidative stress plays a major role in the manifestation of gout, including reactive oxygen species (ROS) and pro-inflammatory cytokines (read: inflammation markers). Purine-rich diets are not recommended for those with gout because the metabolism of purines by xanthine oxidase produces urate, but also generates ROS. Anthocyanins and other phenolics use their antioxidant capabilities to interfere with oxidation and scavenge free radicals to decrease urate production. The anti-inflammatory effects of anthocyanins on gout point to inflammatory processes. Hyperuricemia causes a deposition of urate crystals in the tissues, which stimulate inflammation markers, causing the pain and swelling in joints. Anthocyanins are able to inhibit inflammatory processes and reduce gout flares (1).

Gout and Arthritis

In a single-blind, two-phase, randomized crossover study of 12 healthy individuals, Bell et al. found that the consumption of Montmorency tart cherry juice at 30 mL or 60 mL (~500 mg or 1000 mg of anthocyanins), reduced urate levels by 36% (2).

In a case-crossover study by Zhang et al., 633 individuals with gout consumed cherries over a 2-day period and found a 35% lower risk of gout attacks compared to no intake. These findings persisted across subgroups of sex, obesity, purine intake, alcohol use, diuretic use, and anti-gout medications (3).

In a pilot study of 24 gout patients that consumed one tablespoon of tart cherry juice concentrate twice daily for 4 months, Schlesinger et al. found the number of gout flares decreased from an average of 7 per year to 2 flares per year. They also found in laboratory studies that the exposure of inflammatory molecules to cherry juice concentrate reduced the secretion of key inflammatory markers by 60% (4).

Muscle

In a randomized, double blind, placebo-controlled trial, 54 healthy runners ran 26.3 km over a 24 hour period and were given a 355 mL tart cherry juice or a placebo cherry drink twice daily for 7 days prior to the race. Upon assessing their pain level on a Visual Analog Scale before and after the race, Kuehl et al. reported the tart cherry juice group had significantly less muscle pain and soreness (5).

For powdered tart cherry supplements and resistance training, Levers et al. found that amongst 23 healthy, resistance-trained men, short-term supplementation surrounding a single bout of resistance exercise reduced muscle soreness, strength decrement during recovery, and muscle breakdown (6).

Sleep

Tart cherries contain a vast array of phytochemicals, which include the sleep-wake cycle regulator, melatonin. In a randomised, double-blind, placebo-controlled, crossover study, 20 individuals consumed a placebo drink or tart cherry juice concentrate for 7 days. Measuring sleep quality by actigraphy and a sleep questionnaire, Howatson et al. found total melatonin content was significantly elevated in the cherry group compared to placebo, with increased sleep duration and sleep quality in both men and women (7).

Pigeon et al. conducted a randomized, double-blind, crossover pilot study of 15 individuals with chronic insomnia. Assessing sleep onset, total sleep time, and sleep efficiency in receiving 2 weeks of tart cherry juice compared to 2 weeks of no treatment, tart cherry juice significantly reduced insomnia severity, as much as or more than valerian and melatonin, the two most studied sleep supplements (8).

References